Let G be a finitely generated group and X its Cayley graph with respect to a finite, symmetric generating set S. Furthermore, let H be a finite group and H ≀G the lamplighter group (wreath product) over G with group of “lamps” H. We show that the spectral measure (Plancherel measure) of any symmetric “switch–walk–switch” random walk on H ≀G coincides with the expected spectral measure (integrat...

we consider gabor systems generated by a gaussian function and prove certain classical results of paley and wiener on nonharmonic fourier series of complex exponentials for the gabor expansion‎. ‎in particular, we prove a version of plancherel-po ́lya theorem for entire functions with finite order of growth and use the hadamard factorization theorem to study regularity‎, ‎exactness and deficienc...

There are some new developments on Plancherel formula and growth of matrix coefficients for unitary representations of nilpotent Lie groups. These have several consequences for the geometry of weakly symmetric spaces and analysis on parabolic subgroups of real semisimple Lie groups, and to (infinite dimensional) locally nilpotent Lie groups. Many of these consequences are still under developmen...

In this paper we address sampling and approximation of functions on combinatorial graphs. We develop filtering on graphs by using Schrodinger’s group of operators generated by combinatorial Laplace operator. Then we construct a sampling theory by proving Poincare and Plancherel-Polya-type inequalities for functions on graphs. These results lead to a theory of sparse approximations on graphs and...

In this paper, we study the asymptotic behavior of traces Hecke operators for spherical discrete automorphic representations fixed level on general split reductive groups over \(\mathbb {Q}\). Under a condition analytic intertwining operators, which is known classical and exceptional group \(G_2\), obtain expected asymptotics in terms Plancherel measure an explicit estimate remainder.